The Blériot-SPAD S.91 was a French light-weight fighter aircraft. It would be later developed into the Blériot-SPAD S.510, the last biplane produced by the French aeronautic industries.

The Blériot SPAD S.510 was a French single-seat, single-engined biplane fighter aircraft. First flying in 1933, 60 were built for the Armée de l'Air, entering service in 1936. The type remained in service as a fighter-trainer at the start of the Second World War. It was the last French biplane fighter to enter production.